High performance automobiles use aerodynamic elements to generate downward force (or downforce) on the vehicle to increase contact with the road, and provide increased stability and control. One of the most common aerodynamic elements for generating such downforce is a rear wing. A multitude of different criteria must be considered when designing a rear wing. These include downforce, drag, weight-to-strength ratio, performance at different speeds, performance during straightaways and curves, and visual aesthetics.
Rear wings that properly balance other considerations when the vehicle is traveling on a straightaway, too often suffer a precipitous loss of downforce when in yaw. Yaw is experienced, for example, when the vehicle is transitioning to, or when the vehicle is in, a cornering attitude. Yaw causes turbulence over the wing that reduces the downforce, resulting from a reduced aerodynamic effect of the airfoil element of the wing.
Similarly, rear wings that properly balance other considerations often require too much weight in order to provide the necessary strength (i.e., too high a weight-to-strength ratio). Spacing the wing sufficiently above a rear surface of the automobile is also desirable for minimizing turbulence over the airfoil surface of the wing. This further permits the rear surface itself to be shaped to have its own aerodynamic effect. As a result of mounting such a wing a distance above the rear surface of the vehicle, the additional weight resulting from the high weight-to-strength ratio effectively raises the center of gravity of the vehicle, creating its own potential stability and control negatives.
The visual aesthetics resulting from the combination of the wing with the automobile are also important. Indeed, improved visual aesthetics often improves the desired aerodynamic effect; i.e., downforce. This is because the aerodynamic effects of the wing will either fight against or work with the aerodynamic effects of the vehicle surfaces, just as the visual effects will either fight against or work with the vehicle surfaces.